The invention relates to an rpm governor for fuel-injected internal combustion engines, in particular a centrifugal governor of an injection pump for Diesel motor vehicle engines.
A centrifugal governor of this kind is already known (German Offenlegungsschrift No. 2 644 994) now U.S. Pat. No. 4,143,634, in which the initial stress of the idling spring is increased when the engine is cold by means of an idling correction apparatus equipped with a thermostat, in order to assure smooth running of the engine. The corrective final control element embodied as a thermostat is heated by a suitable apparatus attached to the electrical control circuit, and the duration of its switched-on time, which is necessary only during the warm-up phase of the engine, is limited by means of a temperature-dependent resistor introduced into the electrical circuit of the heating apparatus, this resistor preferably being embodied as a cold conductor (PTC resistor). This apparatus has the disadvantage that substantial forces must be brought to bear on a part of the thermostat because the idling spring, in order to fix the idling rpm, is already in contact, with a certain initial stress, with an adjustable support element. Furthermore, rapid adjustment of the idling rpm to changed engine loads is not possible in such an apparatus, because it functions relatively slowly and sluggishly.